INTRODUCTION Ageing and several age-related chronic conditions including obesity, insulin resistance and hypertension are associated with mitochondrial dysfunction and represent independent risk factors for atrial fibrillation (AF). MATERIALS AND METHODS Atrial arrhythmogenesis was investigated in Langendorff-perfused young (3-4 month) and aged (>12 month), wild type (WT) and peroxisome proli...

OF THESIS CORRELATION BETWEEN ALTERNANS OF EARLY AND LATE PHASES OF VENTRICULAR ACTION POTENTIAL Several studies suggest that action potential duration (APD) alternans play an important role in initiation of arrhythmias, while less is known about the alternans of early phases of action potential (AP) and phase relation between the two. Transmembrane potentials recorded from swine and canine ven...

The action potential (AP) of a cardiac cell is made up of a complex balance of ionic currents which flow across the cell membrane in response to electrical excitation of the cell. Mathematical models of the action potential have grown increasingly complex and include many subcellular phenomena such as calcium handling and complex Markov formulations of the gating dynamics of the ion channels. T...

The efficacy of Andrographis paniculata (AP) extract was studied on atrazine induced hepatic damage in rats. Ethanolic extract of AP (150mg/kg body weight) was found to protect the male wistar rats from hepato toxic action of atrazine as evidence by significant reduction in the level of lipid peroxidation and increased the antioxidant defense system activity in the atrazine intoxicated rats. Ho...

Repetitive nerve firings cause short-term depression (STD) of release at many synapses. Its underlying mechanism is largely attributed to depletion of a readily releasable vesicle pool (RRP) and a decreased probability of releasing a readily releasable vesicle during an action potential. Which of these two mechanisms is dominant and the mechanism that decreases the release probability remain de...

Pathophysiological remodeling processes at an early stage of an acquired epilepsy are critical but not well understood. Therefore, we examined acute changes in action potential (AP) dynamics immediately following status epilepticus (SE) in mice. SE was induced by intraperitoneal (i.p.) injection of kainate, and behavioral manifestation of SE was monitored for 3-4 h. After this time interval CA1...

The giant alga Chara corallina generates action potentials (APs) in response to mechanical stimulation, injury, or direct electrical stimulation. Students examine the waveform characteristics of these APs using standard intracellular recording techniques. Intracellular recording is easier than with neurons because of the large size of the Chara cell. Students observe very negative resting poten...

Introduction: Oxidative stress is one of the important pathologic factors involved in the pathogenesis of neurodegenerative diseases. Antioxidants as neutralizing agents of free radicals are one of the treatment options for these diseases and antioxidant agents that can pass through blood brain barrier have beneficial effects. In the present research, the antioxidant effect of a new iron ...

Materials and Methods: This prospective study included three groups, 38 patients with Meniere’s disease (41 ears), 30 patients with cochlear hearing loss other than Meniere’s disease (40 ears) and 25 healthy subjects (40 ears). Tympanic membrane ECoG (click and tone-burst evoked) and caloric test were performed. Forty one ears with Meniere’s disease were categorized into definite (28 ears) and ...

Responses to bath-applications of 4-aminopyridine(4-AP) and gamma-aminobutyric acid (GABA) were recorded intracellularly from neurones in the rat isolated superior cervical ganglion. 4-aminopyridine (0.1-1.0 mmol/l) usually induced spontaneous action potentials and excitatory postsynaptic potentials (EPSPs), which were blocked by hexamethonium. Membrane potential was unchanged; spike duration w...